Although Europe can be looked at as an example in terms of what can be done in terms of HSR, inter cty and corridor services, and also commuter and rural services, sadly, night trains have been heavily decimated over the last years. Many trains were eliminated entirely and on those that remain amenities have been cut back. The remaining services mostly run with life-expired cars with no plans for replacement. There are some counter-examples with some investment and even isloated examples of improvement (Caledonian Sleeper, Austrian Nightjet) but these gains are largely blotted out when we look at the vast amount of service that has been lost. Large parts of France, Spain, Germany, all of Denmark etc are now without any form of sleeper train.
Some would suggest that some of these trains have become superfluous due to the growth of HSR, and indeed, there are isolated examples where this is true (Paris to Strasbourg for example). However, many of the lost services are not paralleled by any high speed services or other improvements. The alternative journey by rail often involves multiple changes of train and even staying in a hotel overnight. Thus most people who used to take these trains now prefer to fly instead. The problem is that politicians are often not aware of night trains or their contribution and it is generally difficult to raise much protest when another one comes up for abandonment. Typically in the last years prior to a service being discontinued, they have tinkered around with the schedule, fares and amenities to lose as much patronage as possible so that they could prove nobody actually cares.
Maybe it is because for many states in the US, Amtrak is the only form of rail services, that it is much more visible politically and that congressmen do fight to keep it.
